Dynamic blast closure valve



Jan. 16, 1968 H. L. MASON 3,363,540

DYNAMIC BLAST CLOSURE VALVE Filed May 31, 1966 BLAST WAVE v I N VEN TOR.

HARRY MASON ATTORNEY.

United States Patent 3,363,540 DYNAMIC BLAST 'CLUSURE VALVE Harry L. Mason, Lexington, Ky., assignor to The United States of America as represented by the Secretary of the Navy Filed May 31, 1966, Ser. No. 553,963 7 Claims. (Cl. 98-119) ABSTRACT OF THE DISCLGSURE The description discloses a highly responsive blast actuated closure valve for protecting shelters from the blast and radiation effects from a nuclear or conventional explosion. The valve may include a pair of perforated discs which are mounted in a facing engaging relationship and rotatable with the perforations between an aligned and a misaligned position. A means is provided for interconnecting the discs so that one of the discs is driven by the other while said other disc is rotated. A means which is responsive to a shock wave is also provided for retarding rotation of said other disc upon the occurrence of a nuclear or conventional blast so that said one disc rotates to a position where the perforations are unaligned to prevent entry of any blast effects within the shelter to be protected.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to pressure actuated valves and more particularly to rapid closing blast valves for insulating underground protective shelters or similar structures from blast and radiation efiects of nuclear and conventional explosions.

One of the most important aspects of shelter construcion for protection against nuclear or conventional attack has been the provision of a closure valve for closing the shelter ventilation system or other conduits upon the occurrence of a blast. The simplest designs have been closure valves which are actuated by the blast itself, however these types of valves have been sluggish in their operation due to the necessity of overcoming the inertia of various component masses of the valve to effect closure. Because of the high speed of travel of a shock wave from an explosion, a closure valve which is sluggish in its operation will not serve its intended purpose since the blast wave will enter the shelter before closure can be effected. There has been a long existing need for a blast actuated type of closure valve which will operate instantaneously to close the ventilation system upon the occurrence of an explosion.

Another important consideration in the provision of a closure valve for a shelter ventilation system is that the valve should offer a minimum of impedance to the flow of air within the ventilation ducts. In many shelter ventilation systems fans are used to force a large amount of air into the shelter, thereby calling for entrance ducts which are substantially unimpeded to the incoming air stream. Prior art actuated closure valves have inherently caused a serious impediment to this forced flow of air in that their presence in the ventilation duct presents serious obstructions. It would, therefore, be highly desirable to provide a blast actuated closure Valve which would cause no or substantially no reduction in the desired flow of air within the shelter ventilation system and yet be highly responsive to quickly close the ventilation system upon the occurrence of a nuclear or conventional explosion.

The present invention provides the desired blast actu- 3,3635% Patented Jan. 16, 1%68 ated closure valve in that it is quickly actuated to prevent the shock wave from entering the shelter ventilation system and yet in open position it does not substantially reduce the flow of air to the shelter. This has been accomplished by providing a valve which includes a pair of discs which are rotatably supported in an opposite tacing engaging relationship so that openings within the discs may be aligned and misaligned to open and close a ventilation duct when the discs are rotated between a limited angular relative relationship with respect to one another. A means is provided which interconnects a first one of the discs with the second disc for driving the second disc with the apertures aligned when the first disc is rotated and permits the second disc to rotate through the limited relative angular relationship when the first disc is retarded in its rotation. A means re sponsive to the shock wave for retarding rotation of the first disc is provided to permit the second disc to rotate relative to the first disc to misalign the disc openings and to close the duct upon the occurrence of an explosion. The dynamic action of the rotating discs causes the valve to be highly responsive in its closure action. Further, this dynamic action of the discs offers no or little impedance to the floW of the desired air stream. An important feature of the present invention may be the forming of the openings within the discs in such a manner that the discs operate as fans to force air through the shelter ventilation system. Accordingly, the present closure valve is not only highly responsive to quickly close off the shelter ventilation system, but also can serve a purpose of forcing air through this system. This is a packaged arrangement which has not even been thought possilbe in prior art studies.

An object of the present invention is to provide a dynamic blast actuated closure valve which overcomes the disadvantages of prior art blast actuated closure valves.

Another object is to provide a blast actuated closure valve which is highly responsive in its operation to quickly close off a ventilation duct from blast effects.

A further object is to provide a blast actuated closure valve Which does not cause reduction in the desired flow of ventilation air and yet is highly responsive in its operation to quickly close a ventilation duct from blast effects.

Still another object is to provide a blast actuated closure valve for a ventilation duct wherein the valve forces a large quantity of air through the duct during normal operation and is highly responsive in its operation to quickly close off the duct upon the occurrence of a blast wave.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded isometric view of certain of the elements of the invention;

FIG. 2 is a longitudinal control section of a conduit containing theelements of FIG. 1;

FIG. 3 is a section taken on plane Ill-III of FIG. 2; and

FIG. 4 is a partial section taken along plane IV-lV of FIG. 2.

Referring now to the drawing wherein like reference numerals designate like or corresponding parts throughout the several views, FIGS. 1 and 2 illustrate an exemplary embodiment of the invention which is cooperable with a fluid conduit such as a ventilation duct 10. The ventilation duct may be an air supply duct for a shelter wherein it is desirable that the duct supply suflicient fresh air to meet the occupants needs. Upon the occurrence of an explosion it becomes imperative that the duct be quickly and automatically closed to prevent the entrance of a shock wave into the shelter.

T he exemplary valve 12 includes a first disc 14 and a second disc 16, both rotatably mounted on shaft 18 and retained in proper axial relationship by annular collar 19 and shoulder 21 of shaft 18. Each of the discs has spaced openings which may be equi-angular spaced such as openings 22 through disc 14 and openings 24 through disc 16. During normal operation the discs rotate with the openings 22 and 24 in alignment. With the openings 22 and 24 aligned, air may pass through the duct and supply the shelter. In addition, the openings in both discs may be triangularly shaped with radial side walls 26, 27, 28 and 29 slanted with respect to a plane perpendicular to the axis of rotation of the discs so that the rotating discs act as a fan to assure a strong steady flow of air through the duct. However, under a shock wave condition the discs 14 and 16 are capable of rotating at difierent velocities causing openings 24 of disc 16 to completely misalign relative to the openings 22 of disc 14 so as to position openings 24 adjacent radial portions 30 of disc 14 while radial portions 32 of disc 16 align adjacent openings 22 of disc 14 thereby causing radial disc portions 30 and 32 to effectively close the duct to the passage of a shock wave.

A rotation retarding member 36 is mounted on the shaft 13 by a supporting spider 38 in a position closer to the atmosphere end of the ventilation duct and slightly spaced from disc 14. An annular brake 49 is suitably attached to a support ring 42 which is connected to the supporting spider 38 and which together lie in a substantially perpendicul-ar position to the axis of rotation of the discs. The annular brake 41) is of a material having a high coefficient of friction. The support ring 42 and annular brake 40 have an inner and outer diameter such that the facial area defined by the annular brake is located adjacent an area on disc 14 between its periphery and its openings 22.

A circular dish shaped member 44, located closer to the atmosphere end of the ventilation duct than supporting ring 42, is connected to the support ring by three angularly spaced arms 46. The arms are tapered with the narrower ends connected to the dish member and the wider ends connected to the support ring so as to more evenly distribute a load created by a shock wave impinging on the dish member. The dish member 44 is positioned such that its concave face 48 is fully receptive to a shock wave entering the atmosphere end of the ventilation duct. Spider 38 fits shaft 18 so as to allow slidable motion in a direction toward the disc 14. Motion in a direction away from the disc 14 caused by vibration of the system or the like is prevented by collar 50 attached to shaft 18.

During open operation of the ventilation duct air may pass around the circular dish 44, between the arms 46, through the supporting spider 38 and through the aligned openings. But when the explosion occurs and a shock wave forms, the wave may enter the ventilation duct at its atmosphere end and propagate through the duct first contacting and impinging upon the circular dish 44 on its concave face 48. The pressure of the wave acting on the area of the concave face creates a force acting generally parallel to the longitudinal axis of the duct which force will cause the rotation retarding member 36 to slide along the shaft 18 toward the disc 14. Since the distance between the disc 14 and the annular brake 40 is short the annular brake will quickly contact the disc 14 to retard its angular velocity when the disc 14 is in a rotating condition. The disc 14 may be rotated by a motor 52 through shaft 53 and friction member 54 driving disc 14 at its annular rear face 55. Upward projecting tab 56, FIG. 4, attached to the support ring 42 and downward projecting tab 58 connected to the duct provide means connected to the rotation retarding member 36 and the duct for preventing rotational motion by the rotation retarding member 36 when its annular brake 40 contacts disc 14 under the influence of a shock wave.

Means interconnecting disc 14 with disc 16 for rotating disc 16 at the same velocity as disc 14 while aligning openings 22 with openings 24 and for allowing relative rotation between the discs so as to completely misalign said openings comprises a lost motion mechanism which may consist of pins 60 on disc 16 extending longitudinally toward disc 14 and contacting disc 14 within slots 62, FIGS. 2 and 3. During normal duct operation, when air is supplied to the shelter, pins 60 engage slots 62 at slot ends 64, FIG. 3, causing disc 14 to drive disc 16 at the same angular velocity as disc 14. The introduction of a shock wave causes retardation of disc 14 and the pins 60 will slide toward and contact slot ends 66. When the pins contact slot ends 66, the openings 22 and 24 will be completely misaligned closing the duct.

Shaft 18 is rigidly connected to an annular support through plate members 72. In turn, the annular support has a plurality of drilled holes which correspond to similarly drilled and spaced holes in the duct so as to allow the annular support to be bolted to the duct. By placing the annular support perpendicular to the axis of rotation of the discs and slightly spaced from the discs in a shelter duct end direction, the discs are prevented from being moved toward the shelter end of the duct under the influence of a shock wave acting on the discs and the rotation retarding member 36.

In operation of the invention the disc 14 is rotated at a substantially constant angular velocity in the direction of the arrow, FIG. 1, by the motor 52. Slot ends 64 engage pins 60 of disc 16 and cause disc 16 to rotate in the direction of the arrow at the same angular velocity as disc 14. The openings 22 and 24 will be aligned to allow air to flow through the ventilation duct either to or from the shelter. Since the radial sides 26, 27, 28 and 22 of the openings are slanted, the rotating discs act as a fan unit to increase the flow of air through the duct. Upon the detonation of a nuclear or conventional weapon in the vicinity of the duct, a shock Wave will travel toward the shelter and first impinge upon the circular dish member 48 of the rotation retarding member 36. The force of the shock Wave will cause the retarding member to slide along shaft 18 toward the first rotating disc 14 until frictional contact is made between the disc 14 and the annular brake 40. This contact will retard rotation of disc 14 and will slow the motor due to increased load. The motor may be made to shut oif when overloaded so that it stops driving disc 14.

Disc 16 being in slidable engagement with disc 14 and, therefore, not affected by the rotation retarding member 36, continues to rotate at substantially the same velocity as before the introduction of the shock wave. The lost motion mechanism consisting of pins 69 and slots 62 allows disc 16 to rotate relative to disc 14 until the pins slide from slot ends 64 to slot ends 66. With the pins located at slot ends 66, the openings 24 of disc 16 completely misalign with the openings 22 of disc 14 thereby effectively blocking the shock wave and preventing theshock waves destructive force from reaching the shelter interior. The closure operation described above is ex' tremely quick as the disc openings will quickly misalign as disc 14 is retarded. The discs will remain misaligned until action is taken to return the valve to normal open operation. Prolonged misalignment may be highly desirable in that harmful material from nuclear explosions remaining in the atmosphere or on the earths surface after the explosion Will not be introduced into the shelter through the ventilation duct.

It is now readily apparent that the present invention provides a quickly closing blast closure valve which operates automatically upon a shock wave impinging thereon.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim: 1. A blast actuated closure valve for a conduit communicating atmosphere with a shelter comprising:

first and second discs which have opposite engageable faces; means for rotatably supporting the discs about a common axis within the conduit with the disc faces in engagement; said discs having openings therethrough which are alignable and misalignable to open and close said conduit when the discs are rotated between a limited relative angular relationship with respect to one another; means interconnecting the first disc with the second disc for driving the second disc with the openings aligned when the first disc is rotated and permitting the second disc to rotate through the limited relative angular relationship when the first disc is retarded in its rotation; and means responsive to a shock wave for retarding rotation of the first disc to permit the second disc to rotate relative to the first disc to close said conduit. 2. A valve in accordance with claim 1 wherein the means for retarding rotation comprises:

a member mounted for movement in a direction along said common axis; said member being perforated to communicate with the openings in the discs and including a surface upon which a shock wave may impinge; and said member having a braking surface adapted to move into contact with the first disc. 3. A valve in accordance with claim 2 wherein the means for retarding rotation comprises:

an annular non-rotatable brake adapted to contact the first disc adjacent its periphery; the surface upon which a shock wave may impinge 6 comprising a circular dish member having its axis aligned with said common axis and the dish member being spaced from the first disc with a concave portion thereof facing in a direction toward an 5 atmosphere end of the conduit; and

the circular dish member being connected to the annular brake by a plurality of angularly spaced arm members. 4. A valve in accordance with claim 1 wherein the disc m openings are constructed in the form of a fan for forcibly moving air therethrough.

5. A valve in accordance with claim 1 wherein the disc interconnecting means comprises:

a slot in one of the discs;

a pin on the other disc having a portion disposed in the slot; and said pin engaging the slot at an end thereof when the disc openings are aligned and engaging an opposite end thereof when the disc openings are misaligned.

6. A valve in accordance with claim 1 including a motor operatively connected to the first disc for rotating said disc.

7. A valve in accordance with claim 6 wherein said motor is operatively connected to the first disc by a 25 member frictionally engaging the first disc.

References Cited UNITED STATES PATENTS 3,068,891 12/1962 Panning et al. 251212 3,140,648 7/1964 Bergman et al. 98-119 3,173,356 3/1965 Schierse et al. 98-119 3,232,208 2/1966 Maassen 98119 3,296,952 1/1967 Lingal 98-119 3,301,168 1/1967 Schindler et al. 98119 ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

